Channel Access Configuration

ABSTRACT

Embodiments herein relate to a method performed by a scheduling node ( 12 ) for scheduling an uplink transmission from a wireless device ( 10 ) to the scheduling node ( 12 ), which wireless device ( 10 ) is connected to a Primary Cell, Pcell, of the scheduling node in a licensed or unlicensed frequency band, and wherein the wireless device ( 10 ) is also connected to at least one Secondary Cell, SCell, in an unlicensed frequency band. The scheduling node determines at least one Listen Before Talk, LBT, parameter associated with an LBT procedure and informs the wireless device ( 10 ) about the determined at least one LBT parameter in a scheduling grant of the uplink transmission.

TECHNICAL FIELD

Embodiments herein relate to channel access configuration and inparticular to channel configuration for Long Term Evolution (LTE),MulteFire, LTE-Unlicensed (LTE-U), and Licensed Assisted Access (LAA).

BACKGROUND

In a typical wireless communication network, wireless devices, alsoknown as wireless communication devices, mobile stations, stations (STA)and/or user equipments (UEs), communicate via a Radio Access Network(RAN) to one or more core networks. The RAN covers a geographical areawhich is divided into service areas or cell areas, with each servicearea or cell area being served by an access point e.g. a radio networknode such as a radio access node e.g., a Wi-Fi access point or a radiobase station (RBS), which in some networks may also be denoted, forexample, a “NodeB” or “eNodeB”. The area or cell area is a geographicalarea where radio coverage is provided by the access point. The accesspoint communicates over an air interface operating on radio frequencieswith the wireless device within range of the access point.

A Universal Mobile Telecommunications System (UMTS) is a thirdgeneration telecommunication network, which evolved from the secondgeneration (2G) Global System for Mobile Communications (GSM). The UMTSterrestrial radio access network (UTRAN) is essentially a RAN usingwideband code division multiple access (WCDMA) and/or High Speed PacketAccess (HSPA) for user equipments. In a forum known as the ThirdGeneration Partnership Project (3GPP), telecommunications supplierspropose and agree upon standards for third generation networks and UTRANspecifically, and investigate enhanced data rate and radio capacity. Insome RANs, e.g. as in UMTS, several access points may be connected,e.g., by landlines or microwave, to a controller node, such as a radionetwork controller (RNC) or a base station controller (BSC), whichsupervises and coordinates various activities of the plural accesspoints connected thereto. This type of connection is sometimes referredto as backhaul connection. The RNCs are typically connected to one ormore core networks.

Specifications for the Evolved Packet System (EPS) have been completedwithin the 3rd Generation Partnership Project (3GPP) and this workcontinues in the coming 3GPP releases. The EPS comprises the EvolvedUniversal Terrestrial Radio Access Network (E-UTRAN), also known as theLong Term Evolution (LTE) radio access network, and the Evolved PacketCore (EPC), also known as System Architecture Evolution (SAE) corenetwork. E-UTRAN/LTE is a variant of a 3GPP radio access technologywherein the radio base station nodes are directly connected to the EPCcore network rather than to RNCs. In general, in E-UTRAN/LTE thefunctions of an RNC are distributed between the radio base stations,e.g. eNodeBs in LTE, and the core network. As such, the RAN of an EPShas an essentially “flat” architecture comprising radio base stationsconnected directly to one or more core networks, i.e. they are notconnected to RNCs. To compensate for that, the E-UTRAN specificationdefines a direct interface between radio base stations, this interfacebeing denoted the X2 interface.

The ongoing 3GPP Rel-13 study item “Licensed-Assisted Access” (LAA)intends to allow LTE equipment to also operate in the unlicensed 5 GHzradio spectrum. The unlicensed 5 GHz spectrum is used as a complement tothe licensed spectrum. Accordingly, wireless devices connect in thelicensed spectrum, e.g. in a primary cell (PCell) and use carrieraggregation (CA) to benefit from additional transmission capacity in theunlicensed spectrum e.g. in a secondary cell (SCell). To reduce thechanges required for aggregating licensed and unlicensed spectrum, anLTE frame timing in the primary cell is simultaneously used in thesecondary cell.

Regulatory requirements, however, may not permit transmissions in theunlicensed spectrum without prior channel sensing. Since the unlicensedspectrum must be shared with other radios of similar or dissimilarwireless technologies, a so called listen-before-talk (LBT) method needsto be applied. LBT involves sensing the medium for a pre-defined minimumamount of time and backing off if the channel is busy. Today, theunlicensed 5 GHz spectrum is mainly used by equipment implementing theIEEE 802.11 Wireless Local Area Network (WLAN) standard. This standardis known under its marketing brand “Wi-Fi.”

LTE uses Orthogonal Frequency Division Multiplexing (OFDM) in thedownlink and Discrete Fourier Transform (DFT)-spread OFDM, also referredto as Single-Carrier Frequency Division Multiple Access (SC-FDMA) in theuplink. The basic LTE downlink physical resource can thus be seen as atime-frequency grid as illustrated in FIG. 1, where each resourceelement corresponds to one OFDM subcarrier during one OFDM symbolinterval. The uplink subframe has the same subcarrier spacing as thedownlink and the same number of SC-FDMA symbols in the time domain asOFDM symbols in the downlink.

In the time domain, LTE downlink transmissions are organised into radioframes of 10 ms, each radio frame consisting of ten equally-sizedsubframes of length Tsubframe=1 ms as shown in FIG. 2. Each subframecomprises two slots of duration 0.5 ms each, and the slot numberingwithin a frame ranges from 0 to 19. For normal cyclic prefix, onesubframe consists of 14 OFDM symbols. The duration of each symbol isapproximately 71.4 μs.

Furthermore, the resource allocation in LTE is typically described interms of resource blocks, where a resource block corresponds to one slot(0.5 ms) in the time domain and 12 contiguous subcarriers in thefrequency domain. A pair of two adjacent resource blocks in timedirection (1.0 ms) is known as a resource block pair. Resource blocksare numbered in the frequency domain, starting with 0 from one end ofthe system bandwidth.

Downlink transmissions are dynamically scheduled, i.e., in each subframethe access point transmits control information about which wirelessdevice's data is transmitted to and upon which resource blocks the datais transmitted, in the current downlink subframe. This controlsignalling is typically transmitted in the first 1, 2, 3 or 4 OFDMsymbols in each subframe and the number n=1, 2, 3 or 4 is known as theControl Format Indicator (CFI). The downlink subframe also containscommon reference symbols, which are known to the receiver and used forcoherent demodulation of e.g. the control information. A downlink systemwith CFI=3 OFDM symbols as control is illustrated in FIG. 3.

From LTE Rel-11 onwards, above described resource assignments may alsobe scheduled on the enhanced Physical Downlink Control Channel (EPDCCH).For Rel-8 to Rel-10 only Physical Downlink Control Channel (PDCCH) isavailable.

The reference symbols shown in FIG. 3 may be the cell specific referencesymbols (CRS) and may be used to support multiple functions includingfine time and frequency synchronisation and channel estimation forcertain transmission modes.

The 3GPP LTE Rel-10 standard supports bandwidths larger than 20 MHz. Oneimportant requirement on LTE Rel-10 is to assure backward compatibilitywith LTE Rel-8. This should also include spectrum compatibility. Thatwould imply that an LTE Rel-10 carrier, wider than 20 MHz, should appearas a number of LTE carriers to an LTE Rel-8 terminal. Each such carriermay be referred to as a Component Carrier (CC). In particular for earlyLTE Rel-10 deployments it can be expected that there will be a smallernumber of LTE Rel-10-capable wireless devices compared to many LTElegacy wireless devices. Therefore, it is necessary to assure anefficient use of a wide carrier also for legacy wireless devices, i.e.that it is possible to implement carriers where legacy wireless devicesmay be scheduled in all parts of the wideband LTE Rel-10 carrier. Thestraightforward way to obtain this would be by means of CarrierAggregation (CA). CA implies that an LTE Rel-10 wireless device mayreceive multiple CCs, where the CCs have, or at least the possibility tohave, the same structure as a Rel-8 carrier. CA is illustrated in FIG.4. A CA-capable wireless device is assigned a primary cell (PCell) whichis always activated, and one or more secondary cells (SCells) which maybe activated or deactivated dynamically. A wireless device may in thisdisclosure also be referred to as terminal and may be any of a mobilephone, personal digital assistant, tablet, laptop, or any other devicethat may communicate by means of radio with a node in a Radio AccessNetwork, RAN. Some non-limiting examples of such a wireless devices area vehicle, vending machine, parking meter or any other type of devicehaving communication capabilities to communicate by means of radio withan access point in a RAN.

The number of aggregated CC as well as the bandwidth of the individualCC may be different for uplink and downlink. A symmetric configurationrefers to the case where the number of CCs in downlink and uplink is thesame whereas an asymmetric configuration refers to the case that thenumber of CCs is different. It is important to note that the number ofCCs configured in a cell may be different from the number of CCs seen bya wireless device: A wireless device may for example support moredownlink CCs than uplink CCs, even though the cell is configured withthe same number of uplink and downlink CCs.

In addition, a key feature of carrier aggregation is the ability toperform cross-carrier scheduling. This mechanism allows a (E)PDCCH onone CC to schedule data transmissions on another CC by means of a 3-bitCarrier Indicator Field (CIF) inserted at the beginning of the (E)PDCCHmessages. For data transmissions on a given CC, a wireless deviceexpects to receive scheduling messages on the (E)PDCCH on just oneCC—either the same CC, or a different CC via cross-carrier scheduling.The mapping from (E)PDCCH to Physical Downlink Shared Channel (PDSCH) isalso configured semi-statically.

In typical deployments of WLAN, carrier sense multiple access withcollision avoidance (CSMA/CA) is used for medium access. This means thatthe channel is sensed to perform a clear channel assessment (CCA), and atransmission is initiated only if the channel is declared as Idle, i.e.traffic NOT detected on the channel. In case the channel is declared asBusy, i.e. traffic detected on the channel, the transmission isessentially deferred until the channel is deemed to be Idle. When therange of several Access Points (AP) using the same frequency overlap,this means that all transmissions related to one AP might be deferred incase a transmission on the same frequency to or from another AP which iswithin range may be detected. Effectively, this means that if severalAPs are within range, they will have to share the channel in time, andthe throughput for the individual APs may be severely degraded. Ageneral illustration of the listen before talk (LBT) mechanism is shownin FIG. 5.

A general illustration of the listen before talk (LBT) mechanism isshown in FIG. 5. Action 1. A transmitter performs a CCA using energydetection. The transmitter detects no traffic on the channel. Action 2.The transmitter occupies the channel and starts a data transmission.Furthermore, the transmitter may send Control (Ctrl) signals without(w/o) CCA check denoted as action 5. Action 3. The transmitter remainsidle and starts a CCA in the end of the idle period. Traffic is detectedon the channel and the channel is busy. Action 4. Thus, no transmissionis allowed on the channel as the channel is busy and in the end of theprohibited time the transmitter starts a CCA using energy detection. Thetransmitter detects no traffic on the channel and the transmitteroccupies the channel and starts a data transmission.

Up to now, the spectrum used by LTE is dedicated to LTE. This has theadvantage that LTE system does not need to care about the coexistenceissue and the spectrum efficiency may be maximised. However, thespectrum allocated to LTE is limited which cannot meet the everincreasing demand for larger throughput from applications/services.Therefore, a new study item has been initiated in 3GPP on extending LTEto exploit unlicensed spectrum in addition to licensed spectrum.Unlicensed spectrum may, by definition, be simultaneously used bymultiple different technologies. Therefore, LTE should consider thecoexistence issue with other systems such as IEEE 802.11, also calledWi-Fi. Operating LTE in the same manner in unlicensed spectrum as inlicensed spectrum may seriously degrade the performance of Wi-Fi asWi-Fi will not transmit once the channel is detected as occupied.

SUMMARY

An object of embodiments herein is to provide a mechanism that improvesthe performance of a wireless communication network.

According to an aspect the object is achieved by providing a methodperformed by a scheduling node for scheduling an uplink transmissionfrom a wireless device to the scheduling node. The wireless device isconnected to a Pcell of the scheduling node in a licensed or unlicensedfrequency band, and wherein the wireless device is also connected to atleast one SCell in an unlicensed frequency band. The scheduling nodedetermines at least one LBT parameter associated with an LBT procedure;and informs the wireless device about the determined at least one LBTparameter in a scheduling grant of the uplink transmission.

According to another aspect the object is achieved by providing a methodperformed by a wireless device for performing an uplink transmission toa scheduling node. The wireless device is connected to a Pcell of thescheduling node in a licensed or unlicensed frequency band, and thewireless device is also connected to at least one SCell in an unlicensedfrequency band. The wireless device receives information, in ascheduling grant of the uplink transmission, of at least one LBTparameter associated with an LBT procedure. The wireless device performsthe LBT procedure using the at least one LBT parameter when transmittingdata according to the received scheduling grant.

According to yet another aspect the object is achieved by providing ascheduling node for scheduling an uplink transmission from a wirelessdevice to the scheduling node. The scheduling node is configured toserve a Pcell in a licensed or unlicensed frequency band and whichwireless device is configured to connect to the Pcell, and wherein thewireless device is also configured to connect to at least one SCell inan unlicensed frequency band. The scheduling node is configured todetermine at least one LBT parameter associated with an LBT procedure;and to inform the wireless device about the determined at least one LBTparameter in a scheduling grant of the uplink transmission.

According to yet still another aspect the object is achieved byproviding a wireless device for performing an uplink transmission to ascheduling node, which wireless device is configured to connect to aPcell of the scheduling node in a licensed or unlicensed frequency band.The wireless device is also configured to connect to at least one SCellin an unlicensed frequency band. The wireless device is further beingconfigured to receive information, in a scheduling grant of the uplinktransmission, of at least one LBT parameter associated with an LBTprocedure. The wireless device is further configured to perform the LBTprocedure using the at least one LBT parameter when transmitting dataaccording to the received scheduling grant.

It is herein also provided a computer program comprising instructions,which, when executed on at least one processor, cause the at least oneprocessor to carry out the methods herein, as performed by thescheduling node or the wireless device. Furthermore, it is hereinprovided a computer-readable storage medium, having stored thereon acomputer program comprising instructions which, when executed on atleast one processor, cause the at least one processor to carry out themethods herein, as performed by the scheduling node or the wirelessdevice.

An advantage of embodiments herein is that the use of a suboptimal LBTparameter at the wireless device may be avoided as the determined, e.g.an updated, LBT parameter is informed to the wireless device in thescheduling grant and the channel access probability of the wirelessdevice may thus be improved. This will lead to an improved performanceof the wireless communication network.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments will now be described in more detail in relation to theaccompanying drawings, in which:

FIG. 1 is an illustration of one OFDM symbol including cyclic prefix.

FIG. 2 is an illustration of the LTE time-domain structure.

FIG. 3 is an illustration of a normal downlink subframe.

FIG. 4 is an illustration of carrier aggregation with an aggregatedbandwidth of 100 MHz.

FIG. 5 is an illustration of a Listen Before Talk, LBT, procedure.

FIG. 6 is an illustration of LAA to unlicensed spectrum using LTEcarrier aggregation.

FIG. 7a shows a schematic overview depicting a wireless communicationnetwork according to embodiments herein.

FIG. 7b shows a combined flowchart and signalling scheme according tothe embodiments.

FIG. 7c shows a flowchart depicting a method performed by a schedulingnode according to embodiments herein.

FIG. 7d is an illustration of uplink LAA transmissions based on anuplink LBT protocol.

FIG. 8 is an illustration of joint grant transmission; one downlinksubframe comprising uplink grants for several consecutive subframes.

FIG. 9 is an illustration of joint grant transmission, one subframecomprising uplink grants for several non-consecutive uplink subframes.

FIG. 10 is an illustration of an example of a downlink databuffer-dependent adaptation of the delay between joint uplink granttransmission and uplink burst transmission.

FIG. 11a comprises table 1, which is an example of LBT parameters inform of predefined tables in set s=1, with K=5 and defer period=23 μsfor all k.

FIG. 11b comprises table 2, which are examples of LBT parameters in formof predefined tables in set s=2, with K=8 and defer period=43 μs for allk.

FIG. 12 shows a flowchart depicting a method performed by a wirelessdevice according to embodiments herein.

FIG. 13 is a block diagram of a scheduling ode according to anexemplifying embodiment.

FIG. 14 is a block diagram of a scheduling node according to anotherexemplifying embodiment.

FIG. 15 is a block diagram of an arrangement in a scheduling nodeaccording to an exemplifying embodiment.

FIG. 16 shows a block diagram depicting a wireless device according toembodiments herein.

DETAILED DESCRIPTION

One way to utilise the unlicensed spectrum reliably is to transmitessential control signals and channels on a licensed carrier. That is,as shown in FIG. 6, a wireless device is connected to a PCell in e.g.the licensed band and one or more SCells in the unlicensed band. In thisapplication a secondary cell in unlicensed spectrum is denoted as alicensed-assisted access secondary cell (LAA SCell).

In the unlicensed band, a wireless device or an access point performsLBT in order to access the channel for data transmission or sendingscheduling information. In LAA with uplink, UL, transmission on theunlicensed band, an access point controls the UL scheduling of one ormultiple wireless devices. On the UL, the wireless devices may perform ashort LBT with a limited contention window (CW) before transmission ormay transmit after the completion of a successful defer period, or mayfollow some similar LBT procedure. Each wireless device therefore shouldmaintain a set of UL LBT parameters including the current CW, length ofdefer period, random backoff counter, length of initial CCA (if any),duration of quick CCAs on channels other than the principal randombackoff channel, rate of CW size adaptation (if any), triggers used toadapt CW size, etc.

Uplink Hybrid Automatic Repeat Request (HARQ) in LAA is now asynchronouswith the Physical Hybrid-ARQ Indicator Channel, (PHICH) being absent. Sothe wireless device does not know whether its packet was received andwhether its uplink LBT parameters should be modified until it isexplicitly rescheduled by the scheduling node. In the interim periodbefore new scheduling/rescheduling grants from the scheduling node, thewireless device may therefore be using suboptimal UL LBT parameters.Other examples of a scheduling node are an Access Point, a Base Station,a Radio Base Station, a Base Station Controller, and a Radio NodeController.

A mismatch in UL LBT parameters also makes UL multiplexing moredifficult, since wireless devices scheduled in the same subframe areless likely to transmit simultaneously. The scheduling node generallyhas greater access to network-wide information such as traffic load andmay make better choices for LBT parameters of the scheduled wirelessdevices.

Thus, the choice of parameters used in the LBT procedure prior toaccessing the channel has a major impact on inter-RAT coexistence andthroughput.

It is therefore an object of embodiments herein to ensure that one ormore LBT parameters are regularly or continuously determined e.g.updated and/or adjusted and that a scheduled wireless device is providedwith the determined, updated or adjusted one or more LBT parameters.

Embodiments herein relate to wireless communication networks in general.FIG. 7a is a schematic overview depicting a wireless communicationnetwork 1. The wireless communication network 1 comprises one or moreRANs and one or more CNs. The wireless communication network 1 may use anumber of different technologies, such as Wi-Fi, Long Term Evolution(LTE), LTE-Advanced, 5G, MulteFire, LTE-Unlicensed (LTE-U), LicensedAssisted Access (LAA), Wideband Code Division Multiple Access (WCDMA),Global System for Mobile communications/enhanced Data rate for GSMEvolution (GSM/EDGE), Worldwide Interoperability for Microwave Access(WiMax), or Ultra Mobile Broadband (UMB), just to mention a few possibleimplementations. Embodiments herein relate to recent technology trendsthat are of particular interest in a 5G context such as MulteFire,LTE-Unlicensed (LTE-U), and Licensed Assisted Access (LAA), however,embodiments are also applicable in further development of the existingwireless communication systems such as e.g. WCDMA and LTE.

In the wireless communication network 1, wireless devices e.g. awireless device 10 such as a mobile station, a non-access point (non-AP)STA, a STA, a user equipment and/or a wireless terminals, communicatevia one or more Access Networks (AN), e.g. RAN, to one or more corenetworks (ON). It should be understood by the skilled in the art that“wireless device” is a non-limiting term which means any terminal,wireless communication terminal, user equipment, Machine TypeCommunication (MTC) device, Device to Device (D2D) terminal, or nodee.g. smart phone, laptop, mobile phone, sensor, relay, mobile tablets oreven a small base station communicating within a cell.

The wireless communication network 1 comprises a first access point,denoted as scheduling node 12 providing radio coverage over ageographical area, a first service area 11, of a first radio accesstechnology (RAT), such as LTE, Wi-Fi or similar. The scheduling node 12may be a transmission and reception point e.g. a radio network node suchas a Wireless Local Area Network (WLAN) access point or an Access PointStation (AP STA), an access controller, a base station, e.g. a radiobase station such as a NodeB, an evolved Node B (eNB, eNode B), a basetransceiver station, a radio remote unit, an Access Point Base Station,a base station router, a transmission arrangement of a radio basestation, a stand-alone access point or any other network unit capable ofcommunicating with a wireless device within the area served by thescheduling node 12 depending e.g. on the first radio access technologyand terminology used. The scheduling node 12 may be referred to as aserving access point and communicates with the wireless device 10 withDL transmissions to the wireless device 10 and UL transmissions from thewireless device 10.

Furthermore, the wireless communication network 1 comprises a secondaccess point 13 providing radio coverage over a geographical area, asecond area 14, of a second RAT, such as LTE, Wi-Fi, WiMAX or similar.The second access point 13 may be a transmission and reception pointe.g. a radio network node such as a WLAN access point or an Access PointStation (AP STA), an access controller, a base station, e.g. a radiobase station such as a NodeB, an evolved Node B (eNB, eNode B), a basetransceiver station, a radio remote unit, an Access Point Base Station,a base station router, a transmission arrangement of a radio basestation, a stand-alone access point or any other network unit capable ofcommunicating with a wireless device within the area served by thesecond access point 13 depending e.g. on the second radio accesstechnology and terminology used.

The first and second RAT may be the same or different RATs and the firstservice area 11 may be referred to as a first beam group, first beam ora first cell such as a primary cell (PCell). The second service area 14may be referred to as a second beam group, second beam or a second cellsuch as a secondary cell (SCell). It should be noted that the secondservice area 14 may be provided by the same access point as the firstservice area i.e. by the scheduling node 12.

The scheduling node 12 may coordinate communication with the secondaccess point 13 in the wireless communication network 1. This is done bycommunicating with one another over a backhaul connection, e.g. an X2connection, an S1 connection or similar, between the scheduling node 12and the second access point 13. The scheduling node 12 may scheduletransmissions to and from the wireless device 10 for both the schedulingnode 12 as well as the second access node 13.

The wireless device 10 is configured to perform an LBT procedure totransmit data in the second service area 14. According to embodimentsherein, the LBT parameters of the scheduled device(s), i.e. the wirelessdevice 10, may be dynamically determined or adjusted by the schedulingnode 12 via e.g. L1 signalling. The LBT parameters that may be adjustedinclude: the current CW, length of defer period, random backoffcounters, length of initial CCA (if any), duration of quick CCAs onchannels other than the principal random backoff channel, rate of CWsize adaptation (if any), and triggers used to adapt CW size. An exampleis to signal these parameters in a downlink control information (DCI) ofscheduling grants.

Embodiments herein thus describe different examples of how the LBTparameters of one or more scheduled devices, such as the wireless device10, may be dynamically determined or adjusted by the scheduling node 12when operating in unlicensed bands in second service area 14. The LBTparameters that may be adjusted include as stated above, but is notlimited to, the current CW, length of defer period, random backoffcounters, length of initial CCA (if any), duration of quick CCAs onchannels other than the principal random backoff channel, rate of CWsize adaptation (if any), and triggers used to adapt CW size.

FIG. 7b is a combined flowchart and signalling scheme according toembodiments herein.

Action 701. The scheduling node 12 determines, e.g. adjusts dynamically,at least one LBT parameter associated with an LBT procedure.

Action 702. The scheduling node 12 informs the wireless device 10 aboutthe determined at least one LBT parameter in a scheduling grant of theuplink transmission e.g. for data transmission in licensed spectrum.

Action 703. The wireless device 10 then uses the at least one LBTparameter in the LBT procedure when transmitting data according to thereceived scheduling grant.

The method actions performed by the scheduling node 12, exemplifiedherein as the first access point, for scheduling an uplink transmissionfrom the wireless device 10 to the scheduling node 12 according to someembodiments will now be described with reference to a flowchart depictedin FIG. 7c . The wireless device 10 is connected to the Pcell of thescheduling node 12 in a licensed or unlicensed frequency band. Thewireless device 10 is also connected to at least one SCell in anunlicensed frequency band. The actions do not have to be taken in theorder stated below, but may be taken in any suitable order. Actionsperformed in some embodiments are marked with dashed boxes.

Action 711. The scheduling node 12 determines at least one LBT parameterassociated with an LBT procedure. The at least one LBT parameter may bespecific for the wireless device 10 or is common for a plurality ofwireless devices that are associated with the scheduling node 12. The atleast one LBT parameter may be one of: CW size, length of defer period,random backoff counter, length of initial CCA, duration of quick CCAs onchannels other than the principal random backoff channel, rate of CWsize adaptation, triggers to adapt CW size.

Action 712. The scheduling node 12 may schedule the uplink transmissionto a single subframe or a burst of subframes; and correspondingscheduling information is added to the scheduling grant. The schedulingnode 12 may determine a delay between a joint grant transmission and afirst uplink subframe and to schedule multiple uplink subframes usingthe joint grant transmission. The first uplink subframe is scheduledbased on the determined delay, wherein the delay may be determined basedon a downlink data buffer and the number of uplink subframes scheduledby means of a joint grant is based on the uplink buffer of the wirelessdevice. The delay may take an LBT process into account for the wirelessdevice 10 to perform the LBT before transmitting the UL data.

Action 713. The scheduling node 12 informs the wireless device 10 aboutthe determined at least one LBT parameter in the scheduling grant of theuplink transmission. The scheduling node 12 may inform the wirelessdevice 10 of the at least one LBT parameter by means of a common searchspace on the POOCH, or another downlink control channel. The schedulingnode 12 may inform the wireless device 10 of the at least one LBTparameter by means of broadcasting. The at least one LBT parameter maybe an actual/absolute value of the LBT parameter or an offset to beadded/subtracted to a current value of the LBT parameter. The schedulingnode 12 may determine in action 711 at least two different sets of LBTparameters for the wireless device 10 to be used by the wireless device10 in successive LBT attempts. Which set to be used by the wirelessdevice 10 may be determined according to a predefined rule or predefinedtable and may be signalled to the wireless device 10. The wirelessdevice 10 may be configured with different sets of LBT parameters. Thesets may contain CW sizes in increasing order for consecutive LBTattempts and their corresponding length of defer period. The wirelessdevice 10 may be indicated which set to use by signalling, via higherlayer signalling or L1 signalling. Furthermore, an index of the LBTattempt k, may be signalled to the wireless device 10 as well.

Action 714. The scheduling node 12 may signal, to the wireless device10, a maximum transmission duration. E.g. in unlicensed spectrum, thewireless device can transmit continuously only up to the maximumtransmission duration, according to regulation e.g., 6 ms or 8 ms, notneeding to perform LBT during the transmission duration.

An example of an LAA uplink transmission spanning several subframessubsequent to a successful uplink LBT procedure is shown in FIG. 7 d.

The uplink, UL, LBT is performed prior to an UL transmission based on apreviously-received UL resource grant sent by the scheduling SCell orPCell. Multiple wireless devices may perform LBT procedures in parallelif they have been scheduled in the same UL subframe.

The major LBT parameters of the LBT procedure performed by the wirelessdevices may include:

-   -   the current CW (upper and/or lower limit),    -   length of defer period,    -   random backoff counters, where separate random backoff counters        may be used for separate unlicensed channels,    -   length of initial CCA (if any),    -   duration of quick CCAs on channels other than the principal        random backoff channel, if the full LBT procedure with random        backoff is performed only on one such channel,    -   rate of CW size adaptation (if any), and/or    -   triggers used to adapt CW size.

In the following, different example embodiments in which one or more ofthe above LBT parameters may be signalled by the scheduling node 12 areprovided. The adaptation of parameters may be performed by signalling anabsolute value of the new parameter(s), or by signalling a differentialquantity by which to step up or step down the current parameter value.The time duration for which the signalled parameters should be adoptedby the scheduled devices may also be included in the LBT parametersignalling, or may be defined semi-statically using higher-layersignalling. A subset of the above LBT parameters may also be signalledusing higher-layer signalling. A non-limiting example of said higherlayer signalling is the radio resource control (RRC) layer signalling inLTE.

In a first exemplifying embodiment, the one or more LBT parameters aresignalled using new fields in e.g. the DCI associated with resourceallocation grants sent on the (E)PDCCH. These grants may typically belocated in the wireless device-specific search space. The schedulinggrants containing the at least one LBT parameter may correspond to asingle subframe or a burst of subframes such as in a joint grant on aparticular channel, or a single subframe or burst of subframes acrossmultiple channels, such as in a multi-carrier grant. The multiplesubframes scheduled by a joint grant are not necessarily consecutive.FIG. 8 illustrates an example of a joint grant transmission where one DLsubframe contains UL grants for several consecutive UL subframes. FIG. 9illustrates another example of a joint grant transmission withnon-consecutive UL subframes. In the following L is the number of ULsubframes scheduled by the joint grant. Hardware limitations may imposea minimum delay between the joint grant reception and the start of thefirst scheduled UL subframe. δ is the minimum number of subframesrequired between the start of the DL subframe with the joint grant andthe start of the first UL subframe. In the example of FIG. 8 and FIG. 9,L=4 and δ=4.

As a non-limiting example, the scheduling node 12 may signal a commonrandom backoff counter to all wireless devices scheduled for ULtransmission starting in the same subframe or burst of subframes.

In another non-limiting example, the scheduling node 12 may signalwireless devices, i.e. scheduled devices, to adopt only a defer periodwithout additional random backoff for a particular UL subframe or burstof subframes.

In another non-limiting example, the scheduling node 12 may signal acommon random backoff counter and defer period to all wireless devicesscheduled for UL transmission starting in the same subframe or burst ofsubframes.

In a second exemplifying embodiment, the LBT parameters that should beadopted by multiple wireless devices, e.g. scheduled devices, associatedwith the scheduling node 12 is signalled in the common search spacewhich is typically used for paging, transmit power control commands, andsystem information signalling. A new RNTI may be defined for thispurpose. The common search space is for example, a common POOCH controlregion in a subframe that is known to a plurality of devices.

In a third exemplifying embodiment, the LBT parameters may be embeddedin broadcast signals such as the Discovery reference Signal (DRS) orSystem Information Blocks (SIB). Here, the adaptation of LBT parametersmay be on a slower time scale compared to the use of scheduling grants.

In a fourth exemplifying embodiment, the wireless device 10 may begranted resource in the UL spanning longer than the allowed maximumtransmission duration of a wireless device or a set of wireless devices.The wireless device 10 may after the maximum transmission duration re-dothe channel access scheme to check whether it may continue transmittingwithin another transmission duration. The maximum transmission durationmay be signalled to the wireless device 10 within the DCI formatdirectly, e.g. as a specific subframe where the channel access schemeshall be performed as a counter based on the number of subframe thewireless device 10 is allowed to transmit. Another option is that thewireless device 10 is signalled by higher layer what the maximumtransmission duration is. Yet another option is that it is always fixedto a specific value.

In a fifth exemplifying embodiment, the scheduling node 12 schedulesmultiple UL subframes using a joint grant transmission and the delaybetween the joint grant transmission and the first UL subframe isdetermined according to the downlink (DL) data buffer. In thisembodiment the first UL subframe signalled in the joint granttransmitted by the scheduling node 12 depends on the downlink (DL) databuffer.

FIG. 10 gives an example of how this may be applied if the accumulatedduration of all L UL subframes scheduled by means of a joint grant doesnot exceed the maximum allowed transmission duration and if δ<=L. InFIG. 10 is δ=L=4. When the scheduling node 12 has DL data in the bufferto be transmitted to any served wireless device, the UL granttransmitted in subframe n corresponds to a first UL subframe starting insubframe n+δ. This enables to fill in the subframes n to n+δ−1 with DLdata. When the scheduling node 12 does not have DL data in buffer, thejoint UL grant transmitted in subframe n corresponds to an UL burststarting in subframe n+L+2. This enables to interlace perfectly the DLsubframes containing the UL grant and the UL subframes without leavingany unscheduled subframe after an initialisation phase, which would leadto reduced UL data rate.

In a sixth exemplifying embodiment, the number of UL subframes scheduledby means of a joint grant is adapted to the UL buffer situation of thewireless device 10, e.g. the scheduled device, to be scheduled. In LTE,estimates of the buffer situation are regularly obtained by thescheduling node 12 e.g. by means of buffer status report (BSR) sent bywireless devices. If the wireless device 10 for which the joint grant isintended has much UL data in the buffer, a large number of UL subframesscheduled in a joint grant is beneficial.

In addition to the buffer situation, the UL spectral efficiency of theto-be-scheduled wireless device 10, obtained via measurements of past ULtransmission or via a prediction or estimation algorithm in thescheduling node 12, may be used to determine the optimal number of ULsubframes to schedule by means of a joint grant. If the scheduledwireless device 10 is able to empty its buffer quickly, only a few ULsubframes must or may be scheduled in a joint grant. Otherwise,long-term scheduling by means of a joint grant may restrictunnecessarily the number of scheduling opportunities for other wirelessdevices.

The number of UL subframes scheduled by means of a joint grant may alsobe adapted to the traffic load, and/or to the length of the queue in theBS scheduler, and/or to the fairness metric of the considered wirelessdevice 10 compared to the fairness metric of other wireless devices,and/or to the traffic type of other active wireless devices. Example: ifthe BS serves other wireless devices with real-time (UL or DL) traffic,such as Voice over IP (VoIP), it might be preferable not to schedule inadvance a large number of subframes to the same wireless device 10, thismay remove the possibility to schedule another wireless device withhighest priority in-between. LBT gaps, indicated by the at least one LBTparameter, may need to be indicated for the multiple UL subframesscheduled via the joint grant, which is indicating the UL scheduling.

In a seventh exemplifying embodiment, the wireless devices may beconfigured with different sets of LBT parameters. The sets may containthe CW sizes in increasing order for consecutive LBT attempts and theircorresponding length of defer period. Based on pre-defined rules, orpre-defined tables the scheduled device knows how to change the LBTparameters in consecutive LBT attempts for a particular transmissionburst. Examples are given for two sets in table 1 in FIG. 11a and table2 in FIG. 11b where s is the table index, K is the maximum size of theset, k is the LBT attempt modulo K, and CWs(k) is the size of the CW forthe set s and LBT attempt k modulo K. Table 1 illustrates an example ofLBT parameters in form of pre-defined tables in set s=1, with K=5 anddefer period=23 μs for all k; and table 2 illustrates examples of LBTparameters in form of pre-defined tables in set s=2, with K=8, and deferperiod=43 μs for all k

In a non-limiting example the scheduled device, i.e. the wireless device10, is indicated which set to use by signalling s via higher layersignalling or L1 signalling. The wireless device 10 may also bepreconfigured to use a default set, and only change the set if it issignalled to do so, by RRC or L1 signalling.

Moreover, the wireless device 10 determines the CW size by using k,being LBT attempt modulo K, according to the tables or pre-definedrules. Via higher layer or L1 signalling, for example one bit, thescheduled device knows if it has to reset the CW to minimum, i.e. toCWs(k=0) or not. Otherwise, it determines the corresponding CW sizebased on the parameter k and s.

In another non-liming example, the wireless device 10 resets the CW sizeto minimum if some conditions are met without being signalled to do so.Some examples of the triggers for resetting the CW to minimum are asfollows:

-   -   The wireless device 10 may be granted resource in the UL        spanning longer than the allowed maximum transmission duration        of a wireless device or a set of wireless devices. The wireless        device 10 is signalled to reset the CW size for the LBT attempt        after the maximum transmission duration, in order to check        whether it may continue transmitting within another transmission        duration.    -   The wireless device 10 may be granted resources in the UL        spanning longer than the allowed maximum transmission duration        of a wireless device or a set of wireless devices. The wireless        device 10 may after the maximum transmission duration re-do the        channel access scheme to check whether it may continue        transmitting within another transmission duration by resetting        the CW size.    -   The wireless device 10 may be granted resources in the UL        spanning longer than one subframe. The wireless device 10 is        signalled to reset the CW size for the LBT attempts taking place        with an offset from the UL grant after a specific subframe or at        specific subframe(s) within the granted resources.    -   The wireless device 10 may be granted resources in the UL        spanning longer than one subframe. The wireless device 10 resets        the CW size for the LBT attempts taking place with an offset        from the UL grant after a specific subframe or at specific        subframe(s) within the granted resources.        -   The offset from the UL grant may be for example a default            value of be RRC configured or signalled via L1 signalling.        -   An example for a rule to determine the specific subframes            may be every other subframe after that offset as specific            subframes.

In another non-limiting example, the index of the LBT attempt k, may besignalled to the wireless device 10 as well.

The method actions performed by the wireless device 10 for performingthe uplink transmission to the scheduling node 12, according to someembodiments will now be described with reference to a flowchart depictedin FIG. 12. The actions do not have to be taken in the order statedbelow, but may be taken in any suitable order. Actions performed in someembodiments are marked with dashed boxes. The wireless device 10 isconnected to the Pcell of the scheduling node 12 in the licensed orunlicensed frequency band, and the wireless device 10 is also connectedto at least one SCell in the unlicensed frequency band.

Action 1201. The wireless device 10 may receive, from the schedulingnode 12, configuring information indicating different sets of LBTparameters.

Action 1202. The wireless device 10 receives information, in thescheduling grant of the uplink transmission, of the at least one LBTparameter associated with an LBT procedure. For example, the wirelessdevice 10 may receive the information by means of a common search spaceon a PDCCH or another downlink control channel, or receive theinformation in a broadcast. Information. The wireless device 10 mayalternatively or additionally receive information which set to use byreceiving via higher layer signalling or L1 signalling.

Action 1203. The wireless device 10 performs the LBT procedure using theat least one LBT parameter when transmitting data according to thereceived scheduling grant. The wireless device 10 may be configured touse a default set and only change the set when signalled to do so by RRCsignalling or L1 signalling.

Action 1204. The wireless device 10 may change the at least one LBTparameter in consecutive LBT attempts for a particular transmissionburst based on pre-defined rules, or pre-defined tables.

Action 1205. The wireless device 10 may receive, from the schedulingnode 12, the maximum transmission duration.

Action 1206. In some embodiments the at least one LBT parametercomprises a CW size and the wireless device 10 may reset the CW size toa minimum value if some conditions are met.

FIG. 13 is a block diagram of the scheduling node 12 according to anexemplifying embodiment of the scheduling node 12 for scheduling theuplink transmission from the wireless device 10 to the scheduling node12. The scheduling node 12 is configured to serve the Pcell in alicensed or unlicensed frequency band and which wireless device 10 isconfigured to connect to the Pcell. The wireless device 10 is alsoconfigured to connect to at least one SCell in an unlicensed frequencyband. FIG. 13 illustrates the scheduling node 12 comprising a processor1321 and memory 1322, the memory comprising instructions, e.g. by meansof a computer program 1323, which when executed by the processor 1321causes the scheduling node 12 to perform a method according to thesolution according to the different examples and embodiments describedherein.

The processor 1321, and/or the scheduling node 12 may be configured todetermine at least one LBT parameter associated with the LBT procedure.The at least one LBT parameter may be specific for the wireless deviceor is common for a plurality of wireless devices that are associatedwith the scheduling node 12. The at least one LBT parameter may be oneof: CW size, length of defer period, random backoff counter, length ofinitial CCA, duration of quick CCAs on channels other than the principalrandom backoff channel, rate of CW size adaptation, triggers to adapt CWsize. The at least one LBT parameter may be an actual/absolute value ofthe LBT parameter or an offset to be added/subtracted to a current valueof the LBT parameter.

The processor 1321, and/or the scheduling node 12 may be configured toinform the wireless device 10 about the determined at least one LBTparameter in a scheduling grant of the uplink transmission.

The processor 1321, and/or the scheduling node 12 may be configured toschedule the uplink transmission to a single subframe or a burst ofsubframes; and to add corresponding scheduling information to thescheduling grant.

The processor 1321, and/or the scheduling node 12 may be configured toschedule the uplink transmission by being configured to determine adelay between the joint grant transmission and the first uplink subframeand to schedule multiple uplink subframes using the joint granttransmission. The processor 1321, and/or the scheduling node 12 may thenbe configured to schedule the first uplink subframe based on thedetermined delay, and wherein the processor 1321, and/or the schedulingnode 12 may be configured to determine the delay based on a downlinkdata buffer and schedule the number of uplink subframes by means of ajoint grant based on the uplink buffer of the wireless device.

The processor 1321, and/or the scheduling node 12 may be configured toinform the wireless device of the at least one LBT parameter by means ofa common search space on the PDCCH or another downlink control channel.

The processor 1321, and/or the scheduling node 12 may be configured toinform the wireless device of the at least one LBT parameter by means ofbroadcasting.

The processor 1321, and/or the scheduling node 12 may be configured tosignal, to the wireless device 10, a maximum transmission duration.

The processor 1321, and/or the scheduling node 12 may be configured todetermine the at least one LBT parameter by being configured todetermine at least two different sets of LBT parameters for the wirelessdevice 10 to be used by the wireless device 10 in successive LBTattempts. The processor 1321, and/or the scheduling node 12 may beconfigured to determine which set to be used by the wireless device 10according to a predefined rule or predefined table and the processor1321, and/or the scheduling node 12 may be configured to signal whichset to use to the wireless device 10.

FIG. 13 also illustrates the scheduling node 12 comprising a memory1310. It shall be pointed out that FIG. 13 is merely an exemplifyingillustration and memory 1310 may be optional, be a part of the memory1322 or be a further memory of the scheduling node 12. The memory mayfor example comprise information relating to the scheduling node 12, tostatistics of operation of the scheduling node 12, just to give a coupleof illustrating examples. FIG. 13 further illustrates the schedulingnode 12 comprising processing means 1320, which comprises the memory1322 and the processor 1321. Still further, FIG. 13 illustrates thescheduling node 12 comprising a communication unit 1330. Thecommunication unit 1330 may comprise an interface through which thescheduling node 12 communicates with other nodes, devices, UEs orentities of the communication network FIG. 13 also illustrates thescheduling node 12 comprising further functionality 1340. The furtherfunctionality 1340 may comprise hardware of software necessary for thescheduling node 12 to perform different tasks that are not disclosedherein. Merely as an illustrative example, the further functionality maycomprise a scheduler for scheduling transmissions from the schedulingnode 12 and/or for transmissions from scheduled devices with which thescheduling node 12 communicates with.

FIG. 14 is a block diagram of the scheduling node 12 according toanother exemplifying embodiment. FIG. 14 illustrates the scheduling node12 comprising a determining unit 1403, which could also be denoted anupdating unit or adjusting unit etc., for determining and/orupdating/adjusting at least one LBT parameter for the wireless device10. FIG. 14 illustrates the scheduling node 12 further comprising aninformation unit 1404, which could also be denoted transmitting unit ornotification unit etc., for informing concerned scheduled wirelessdevice(s) about the determined/adjusted/updated LBT parameters to beused by the scheduled wireless device(s) hereinafter until furthernotice, e.g. until they are anew determined/adjusted/updated.

The determining unit 1403 may be configured to determine at least oneLBT parameter associated with the LBT procedure.

The information unit 1404 may be configured to inform the wirelessdevice 10 about the determined at least one LBT parameter in ascheduling grant of the uplink transmission.

The scheduling node 12 may comprise a scheduler 1405. The scheduler maybe configured to schedule the uplink transmission to a single subframeor a burst of subframes; and to add corresponding scheduling informationto the scheduling grant.

The scheduler 1405 may be configured to schedule the uplink transmissionby being configured to determine a delay between the joint granttransmission and the first uplink subframe and scheduling multipleuplink subframes using the joint grant transmission. The scheduler 1405may then be configured to schedule the first uplink subframe based onthe determined delay, and wherein the scheduler 1405 may be configuredto determine the delay based on a downlink data buffer and schedule thenumber of uplink subframes by means of the joint grant based on theuplink buffer of the wireless device.

The information unit 1404 may be configured to inform the wirelessdevice of the at least one LBT parameter by means of a common searchspace on the POOCH or another downlink control channel.

The information unit 1404 may be configured to inform the wirelessdevice of the at least one LBT parameter by means of broadcasting.

The information unit 1404 may be configured to signal, to the wirelessdevice 10, a maximum transmission duration.

The determining unit 1403 may be configured to determine the at leastone LBT parameter by being configured to determine at least twodifferent sets of LBT parameters for the wireless device 10 to be usedby the wireless device 10 in successive LBT attempts. The determiningunit 1403 may be configured to determine which set to be used by thewireless device 10 according to a predefined rule or predefined tableand the information unit 1404 may be configured to signal which set touse to the wireless device 10.

In FIG. 14, the scheduling node 12 is also illustrated comprising acommunication unit 1401. Through this unit, the scheduling node 12 isadapted to communicate with other nodes, devices, UEs and/or entities inthe wireless communication network. The communication unit 1401 maycomprise more than one receiving arrangement. For example, thecommunication unit 1401 may be connected to both a wire and an antenna,by means of which the scheduling node 12 is enabled to communicate withother nodes, devices, UEs and/or entities in the wireless communicationnetwork. Similarly, the communication unit 1401 may comprise more thanone transmitting arrangement, which in turn is connected to both a wireand an antenna, by means of which the scheduling node 12 is enabled tocommunicate with other nodes, devices, UEs and/or entities in thewireless communication network. The scheduling node 12 further comprisesa memory 1402 for storing data. Further, the scheduling node 12 maycomprise a control or processing unit (not shown) which in turn isconnected to the different units 1403-1404. It shall be pointed out thatthis is merely an illustrative example and the scheduling node 12 maycomprise more, less or other units or modules which execute thefunctions of the scheduling node 12 in the same manner as the unitsillustrated in FIG. 14.

It should be noted that FIG. 14 merely illustrates various functionalunits in the scheduling node 12 in a logical sense. The functions inpractice may be implemented using any suitable software and hardwaremeans/circuits etc. Thus, the embodiments are generally not limited tothe shown structures of the scheduling node 12 and the functional units.Hence, the previously described exemplary embodiments may be realised inmany ways. For example, one embodiment includes a computer-readablemedium having instructions stored thereon that are executable by thecontrol or processing unit for executing method steps (according to thesolution described herein by means of several examples and embodiments)in the scheduling node 12. The instructions executable by the computingsystem and stored on the computer-readable medium perform the methodsteps of the scheduling node 12 according to the herein describedembodiments and examples.

FIG. 15 schematically shows an embodiment of an arrangement 1500 in thescheduling node 12. Comprised in the arrangement 1500 in the schedulingnode 12 are here a processing unit 1506, e.g. with a Digital SignalProcessor, DSP. The processing unit 1506 may be a single unit or aplurality of units to perform different actions of procedures describedherein. The arrangement 1500 of the scheduling node 12 may also comprisean input unit 1502 for receiving signals from other entities, and anoutput unit 1504 for providing signal(s) to other entities. The inputunit and the output unit may be arranged as an integrated entity or asillustrated in the example of FIG. 14, as one or more interfaces 1401.

Furthermore, the arrangement in the scheduling node 12 comprises atleast one computer program product 1508 in the form of a non-volatilememory, e.g. an Electrically Erasable Programmable Read-Only Memory,EEPROM, a flash memory and a hard drive. The computer program product1508 comprises a computer program 1510, which comprises code means,which when executed in the processing unit 1506 in the arrangement 1500in the scheduling node 12 causes the scheduling node 12 to perform theactions according to the solution as described herein by means of thevarious embodiments and examples.

The computer program 1510 may be configured as a computer program codestructured in computer program modules 1510 a-1510 e. Hence, in anexemplifying embodiment, the code means in the computer program of thescheduling node 12 comprises a determining unit, or module, fordetermining/adjusting/updating one or more LBT parameters. The computerprogram further comprises an informing unit, or module, forinforming/transmitting/notifying a scheduled device about thedetermined/adjusted/updated one or more LBT parameters.

The computer program modules could essentially perform the actions ofthe solution as described, to emulate the determining/adjusting/updatingone or more LBT parameters. In other words, when the different computerprogram modules are executed in the processing unit 1506, they maycorrespond to the units 1403-1404 of FIG. 14.

Although the code means in the embodiments disclosed above inconjunction with FIG. 14 are implemented as computer program moduleswhich when executed in the processing unit causes the scheduling node toperform the actions described above in the conjunction with figuresmentioned above, at least one of the code means may in alternativeembodiments be implemented at least partly as hardware circuits.

FIG. 16 is a block diagram depicting the wireless device 10 forperforming the uplink transmission to the scheduling node 12 accordingto embodiments herein. The wireless device 10 is configured to connectto the Pcell of the scheduling node 12 in a licensed or unlicensedfrequency band and the wireless device 10 is also configured to connectto at least one SCell in an unlicensed frequency band.

The wireless device 10 comprises a processing means 1620, e.g. one ormore processors, configured to perform the methods herein.

The wireless device 10 may comprise a receiving module 1621. Thewireless device 10, the processing means 1620 and/or the receivingmodule 1621 may be configured to receive information, in the schedulinggrant of the uplink transmission, of at least one LBT parameterassociated with the LBT procedure.

The wireless device 10 may comprise a performing module 1622. Thewireless device 10, the processing means 1620 and/or the performingmodule 1622 may be configured to perform the LBT procedure using the atleast one LBT parameter when transmitting data according to the receivedscheduling grant.

The wireless device 10, the processing means 1620 and/or the receivingmodule 1621 may be configured to receive the information by means of thecommon search space on the POOCH or another downlink control channel, orreceive the information in a broadcast.

The wireless device 10, the processing means 1620 and/or the receivingmodule 1621 may be configured to receive, from the scheduling node 12,the maximum transmission duration.

The wireless device 10, the processing means 1620 and/or the receivingmodule 1621 may be configured to further receive from the schedulingnode 12, configuring information indicating different sets of LBTparameters.

The wireless device 10, the processing means 1620 and/or the performingmodule 1622 may be configured to change the at least one LBT parameterin consecutive LBT attempts for a particular transmission burst based onpre-defined rules, or pre-defined tables.

The wireless device 10, the processing means 1620 and/or the receivingmodule 1621 may be configured to further receive information which setto use by receiving via higher layer signalling or L1 signalling.

The wireless device 10, the processing means 1620 and/or the performingmodule 1622 may be configured to use a default set and only change theset when signalled to do so by RRC signalling or L1 signalling.

The wireless device 10 may comprise a resetting module 1623. Thewireless device 10, the processing means 1620 and/or the resettingmodule 1623 may, when the at least one LBT parameter comprises the CWsize, be configured to reset the CW size to a minimum value if someconditions are met.

The methods according to the embodiments described herein for thewireless device are respectively implemented by means of e.g. a computerprogram 1611 or a computer program product, comprising instructions,i.e., software code portions, which, when executed on at least oneprocessor, cause the at least one processor to carry out the actionsdescribed herein, as performed by the wireless device. The computerprogram 1611 may be stored on a computer-readable storage medium 1612,e.g. a disc or similar. The computer-readable storage medium 1612,having stored thereon the computer program, may comprise theinstructions which, when executed on at least one processor, cause theat least one processor to carry out the actions described herein, asperformed by the wireless device 10. In some embodiments, thecomputer-readable storage medium may be a non-transitorycomputer-readable storage medium.

The wireless device 10 further comprises a memory 1610, communicationunit 1630 and further functionality 1640. The memory comprises one ormore units to be used to store data on, such as LBT parameters,scheduled resources, grants, transmit power, applications to perform themethods disclosed herein when being executed, and similar.

The processor may be a single Central Processing Unit, CPU, but couldalso comprise two or more processing units. For example, the processormay include general purpose microprocessors; instruction set processorsand/or related chips sets and/or special purpose microprocessors such asApplication Specific Integrated Circuits, ASICs. The processor may alsocomprise board memory for caching purposes. The computer program may becarried by a computer program product connected to the processor. Thecomputer program product may comprise a computer readable medium onwhich the computer program is stored. For example, the computer programproduct may be a flash memory, a Random-Access Memory RAM, Read-OnlyMemory, ROM, or an EEPROM, and the computer program modules describedabove could in alternative embodiments be distributed on differentcomputer program products in the form of memories within the schedulingnode.

It is to be understood that the choice of interacting units, as well asthe naming of the units within this disclosure are only for exemplifyingpurpose, and nodes suitable to execute any of the methods describedabove may be configured in a plurality of alternative ways in order tobe able to execute the suggested procedure actions.

It should also be noted that the units described in this disclosure areto be regarded as logical entities and not with necessity as separatephysical entities.

According to an aspect a method performed by a scheduling node isprovided for scheduling an uplink transmission from a wireless devicesto the scheduling node. The scheduling node and the wireless device maysupport carrier aggregation, wherein the wireless device may beassociated with the scheduling node by means of being connected to aPrimary Cell, Pcell, in a licensed or unlicensed frequency band, thewireless device may also be connected to at least one Secondary Cell,SCell, in an unlicensed frequency band. The wireless device may also inthis disclosure be referred to as a scheduled device, a UE, a device tobe scheduled and/or a terminal.

The method may comprise determining/updating/adjusting at least one LBTparameter associated with a LBT procedure. The method may also compriseinforming the wireless device about the determined/updated at least oneLBT parameter.

In an example, the at least one LBT parameter is specific for thewireless device.

In another example, the at least one LBT parameter is common for aplurality of wireless devices that are associated with the schedulingnode 12.

In yet another example, the scheduling node 12 may inform the wirelessdevice of the determined/updated/adjusted at least one LBT parametere.g. by means of a Downlink Control Information, DCI, of the schedulinggrant.

In an example, the scheduling grant may comprise LBT parameter(s)relating to a single subframe or a burst of subframes.

In a further example, the single subframe or burst of subframes is to betransmitted on a single channel or across multiple channels.

Further, in an example, the scheduling node informs the device of thedetermined/updated at least one LBT parameter by means of a commonsearch space on the Physical Downlink Control Channel, PDCCH, or anotherdownlink control channel.

Still further, in another example, the scheduling node informs thedevice of the determined/updated at least one LBT parameter by means ofbroadcasting.

In an example, the method may further comprise signalling, to thedevice, a maximum transmission duration.

In another example, the method may further comprise further comprisingdetermining a delay between a joint grant transmission and a firstuplink subframe and scheduling multiple uplink subframes using the jointgrant transmission, wherein the first uplink subframe is scheduled basedon the determined delay.

In yet an example, the delay may be determined based on a downlink databuffer.

In a further example, the number of uplink subframes scheduled by meansof the joint grant may be based on the uplink buffer of the device.

Further, in an example, determining/updating at least one LBT parametermay comprise determining at least two different sets of LBT parametersfor the device to be used by the device in successive LBT attempts.

In yet an example, which set to be used by the device may be determinedaccording to a predefined rule or predefined table.

In still another example, which set to be used by the device issignalled to the device.

Further, in an example, the at least one LBT parameter is one of, butnot limited to, Contention Window (CW) size, length of defer period,random backoff counter, length of initial Clear Channel Assessment(CCA), duration of quick CCAs on channels other than the principalrandom backoff channel, rate of CW size adaptation, triggers to adapt CWsize.

In yet an example, the determined/updated at least one LBT parameter maybe the actual/absolute value of the LBT parameter(s) or anoffset/differential to be added/subtracted to the current value of theLBT parameter(s).

The solution may have several advantages. One possible advantage is thatthe use of suboptimal LBT parameters at one or more devices may beavoided and their channel access probability may be improved. Yetanother possible advantage is that successful multiplexing of multipledevices on the same uplink subframe on the same unlicensed band isenabled. Still another possible advantage is that improved coexistencebetween LAA/standalone LTE-U and WiFi in multi-carrier deployments isenabled. A further possible advantage is that improved coexistencebetween LAA/standalone LTE-U networks of different operators is enabled.

While the embodiments have been described in terms of several examplesand embodiments, it is contemplated that alternatives, modifications,permutations and equivalents thereof may become apparent upon reading ofthe specifications and study of the drawings. Instead, the embodimentsherein are limited only by the following claims and their legalequivalents.

1-40. (canceled)
 41. A method performed by a scheduling node forscheduling an uplink transmission from a wireless device to thescheduling node, wherein the wireless device is connected to a PrimaryCell (Pcell) of the scheduling node in a licensed or unlicensedfrequency band, and wherein the wireless device is also connected to atleast one Secondary Cell (SCell) in an unlicensed frequency band, themethod comprising: determining at least one Listen Before Talk (LBT)parameter associated with an LBT procedure; and informing the wirelessdevice about the determined at least one LBT parameter in a schedulinggrant of the uplink transmission.
 42. The method according to claim 41,further comprising scheduling the uplink transmission to a singlesubframe or a burst of subframes, wherein corresponding schedulinginformation is added to the scheduling grant.
 43. The method accordingto claim 42, wherein the scheduling comprises determining a delaybetween a joint grant transmission and a first uplink subframe andscheduling multiple uplink subframes using the joint grant transmission,wherein the first uplink subframe is scheduled based on the determineddelay, wherein the delay is determined based on a downlink data bufferand the number of uplink subframes scheduled by means of a joint grantis based on an uplink buffer of the wireless device.
 44. The methodaccording to claim 41, wherein the at least one LBT parameter isspecific for the wireless device or common for a plurality of wirelessdevices that are associated with the scheduling node.
 45. The methodaccording to claim 41, wherein the informing comprises informing thewireless device of the at least one LBT parameter by means of a commonsearch space on the Physical Downlink Control Channel (PDCCH) or anotherdownlink control channel.
 46. The method according to claim 41, whereinthe informing comprises informing the wireless device of the at leastone LBT parameter by means of broadcasting.
 47. The method according toclaim 41, further comprising signaling, to the wireless device, amaximum transmission duration.
 48. The method according to claim 41,wherein determining the at least one LBT parameter comprises determiningat least two different sets of LBT parameters for the wireless device tobe used by the wireless device in successive LBT attempts.
 49. Themethod according to claim 48, wherein which set of the at least twodifferent sets of LBT parameters to be used by the wireless device isdetermined according to a predefined rule or predefined table and issignaled to the wireless device.
 50. The method according to claim 41,wherein the at least one LBT parameter is one of: Contention Window (CW)size, length of defer period, random backoff counter, length of initialClear Channel Assessment (CCA), duration of quick CCAs on channels otherthan a principal random backoff channel, rate of CW size adaptation, andtriggers to adapt CW size.
 51. The method according to claim 41, whereinthe at least one LBT parameter is an actual or absolute value of the LBTparameter or an offset to be added or subtracted to a current value ofthe LBT parameter.
 52. A method performed by a wireless device forperforming an uplink transmission to a scheduling node, wherein thewireless device is connected to a Primary Cell (Pcell) of the schedulingnode in a licensed or unlicensed frequency band, and wherein thewireless device is also connected to at least one Secondary Cell (SCell)in an unlicensed frequency band, the method comprising: receivinginformation, in a scheduling grant of the uplink transmission, of atleast one Listen Before Talk (LBT) parameter associated with an LBTprocedure; and performing the LBT procedure using the at least one LBTparameter when transmitting data according to the received schedulinggrant.
 53. The method according to claim 52, wherein the receivingcomprises receiving the information by means of a common search space ona Physical Downlink Control Channel (PDCCH) or another downlink controlchannel, or by receiving the information in a broadcast.
 54. The methodaccording to claim 52, further comprising receiving, from the schedulingnode, a maximum transmission duration.
 55. The method according to claim52, further comprising receiving, from the scheduling node, configuringinformation indicating different sets of LBT parameters.
 56. The methodaccording to claim 55, further comprising changing the at least one LBTparameter in consecutive LBT attempts for a particular transmissionburst based on pre-defined rules or pre-defined tables.
 57. The methodaccording to claim 55, wherein receiving the information furthercomprises receiving information as to which set of the different sets ofLBT parameters to use via higher layer signaling or L1 signaling. 58.The method according to claim 55, wherein the wireless device isconfigured to use a default set of LBT parameters and only change theset when signaled to do so by Radio Resource Control (RRC) signaling orL1 signaling.
 59. The method according to claim 52, wherein the at leastone LBT parameter comprises a Contention Window (CW) size and the methodcomprises resetting the CW size to a minimum value if some conditionsare met.
 60. A scheduling node for scheduling an uplink transmissionfrom a wireless device to the scheduling node, wherein the schedulingnode is configured to serve a Primary Cell (Pcell) in a licensed orunlicensed frequency band, wherein the wireless device is configured toconnect to the Pcell, and wherein the wireless device is also configuredto connect to at least one Secondary Cell (SCell) in an unlicensedfrequency band, the scheduling node comprising: communication circuitryconfigured to communicate directly or indirectly with the wirelessdevice; and processing circuitry operatively associated with thecommunication circuitry and configured to: determine at least one ListenBefore Talk (LBT) parameter associated with an LBT procedure; and informthe wireless device about the determined at least one LBT parameter in ascheduling grant of the uplink transmission.
 61. The scheduling nodeaccording to claim 60, wherein the processing circuitry is configuredto: schedule the uplink transmission to a single subframe or a burst ofsubframes; and add corresponding scheduling information to thescheduling grant.
 62. The scheduling node according to claim 60, whereinthe processing circuitry is configured to schedule the uplinktransmission by being configured to: determine a delay between a jointgrant transmission and a first uplink subframe; schedule multiple uplinksubframes using the joint grant transmission; schedule the first uplinksubframe based on the determined delay; determine the delay based on adownlink data buffer; and schedule the number of uplink subframes, bymeans of a joint grant, based on an uplink buffer of the wirelessdevice.
 63. The scheduling node according to claim 60, wherein the atleast one LBT parameter is specific for the wireless device or commonfor a plurality of wireless devices that are associated with thescheduling node.
 64. The scheduling node according to claim 60, whereinthe processing circuitry is configured to inform the wireless device ofthe at least one LBT parameter by means of a common search space on thePhysical Downlink Control Channel (PDCCH) or another downlink controlchannel.
 65. The scheduling node according to claim 60, wherein theprocessing circuitry is configured to inform the wireless device of theat least one LBT parameter by means of broadcasting.
 66. The schedulingnode according to claim 60, wherein the processing circuitry isconfigured to signal, to the wireless device, a maximum transmissionduration.
 67. The scheduling node according to claim 60, wherein theprocessing circuitry is configured to determine the at least one LBTparameter by being configured to determine at least two different setsof LBT parameters for the wireless device to be used by the wirelessdevice in successive LBT attempts.
 68. The scheduling node according toclaim 67, wherein the processing circuitry is configured to determinewhich set of the at least two different sets of LBT parameters is to beused by the wireless device according to a predefined rule or predefinedtable, and to signal which set to use to the wireless device.
 69. Thescheduling node according to claim 60, wherein the at least one LBTparameter is one of: Contention Window (CW) size, length of deferperiod, random backoff counter, length of initial Clear ChannelAssessment (CCA), duration of quick CCAs on channels other than aprincipal random backoff channel, rate of CW size adaptation, triggersto adapt CW size.
 70. The scheduling node according to claim 60, whereinthe at least one LBT parameter is an actual or absolute value of the LBTparameter or an offset to be added or subtracted to a current value ofthe LBT parameter.
 71. A wireless device for performing an uplinktransmission to a scheduling node, wherein the wireless device isconfigured to connect to a Primary Cell (Pcell) of the scheduling nodein a licensed or unlicensed frequency band, and wherein the wirelessdevice is also configured to connect to at least one Secondary Cell(SCell) in an unlicensed frequency band, the wireless device comprising:communication circuitry configured to communicate with the schedulingnode; and processing circuitry operatively associated with thecommunication circuitry and configured to: receive information, in ascheduling grant of the uplink transmission, of at least one ListenBefore Talk (LBT) parameter associated with an LBT procedure; andperform the LBT procedure using the at least one LBT parameter whentransmitting data according to the received scheduling grant.
 72. Thewireless device according to claim 71, wherein the processing circuitryis configured to receive the information by means of a common searchspace on a Physical Downlink Control Channel (PDCCH) or another downlinkcontrol channel, or by receiving the information in a broadcast.
 73. Thewireless device according to claim 71, wherein the processing circuitryis configured to receive, from the scheduling node, a maximumtransmission duration.
 74. The wireless device according to claim 71,wherein the processing circuitry is configured to further receive fromthe scheduling node, configuring information indicating different setsof LBT parameters.
 75. The wireless device according to claim 74,wherein the processing circuitry is configured to change the at leastone LBT parameter in consecutive LBT attempts for a particulartransmission burst based on pre-defined rules or pre-defined tables. 76.The wireless device according to claim 74, wherein the processingcircuitry is configured to receive information as to which set of thedifferent sets of LBT parameters to use via higher layer signaling or L1signaling.
 77. The wireless device according to claim 74, wherein theprocessing circuitry is configured to use a default set of LBTparameters and to only change the set when signaled to do so by RadioResource Control (RRC) signaling or L1 signaling.
 78. The wirelessdevice according to claim 71, wherein the at least one LBT parametercomprises a Contention Window (CW) size and wherein the processingcircuitry is configured to reset the CW size to a minimum value if someconditions are met.
 79. A non-transitory computer-readable storagemedium, having stored thereon a computer program for scheduling anuplink transmission from a wireless device to a scheduling node, whereinthe wireless device is connected to a Primary Cell (Pcell) of thescheduling node in a licensed or unlicensed frequency band, wherein thewireless device is also connected to at least one Secondary Cell (SCell)in an unlicensed frequency band, and wherein the computer programcomprises instructions that, when executed on at least one processor ofthe scheduling node, cause the scheduling node to: determine at leastone Listen Before Talk (LBT) parameter associated with an LBT procedure;and inform the wireless device about the determined at least one LBTparameter in a scheduling grant of the uplink transmission.
 80. Anon-transitory computer-readable storage medium, having stored thereon acomputer program for performing an uplink transmission from a wirelessdevice to a scheduling node, wherein the wireless device is connected toa Primary Cell (Pcell) of the scheduling node in a licensed orunlicensed frequency band, wherein the wireless device is also connectedto at least one Secondary Cell (SCell) in an unlicensed frequency band,and wherein the computer program comprises instructions that, whenexecuted on at least one processor of the wireless device, cause thewireless device to: receive information, in a scheduling grant of theuplink transmission, of at least one Listen Before Talk (LBT) parameterassociated with an LBT procedure; and perform the LBT procedure usingthe at least one LBT parameter when transmitting data according to thereceived scheduling grant.